The present invention relates generally to optical alignment devices, and more particularly to optical alignment devices which provide a stable reference in the presence of optical source jitter.
In optical systems, such as those employed in optical tracking systems, or satellite communications and detection systems, or the like, it is desirous to known the line-of-sight pointing direction to a high degree of accuracy. This knowledge insures accurate pointing of the optical system to any desired angular position.
It is common for the optical system to include a laser source, or the like, which provides a collimated beam which is used as an optical reference for alignment purposes. The laser source may be located on a gyrostablized platform while the beam propagates throughout the rest of the optical system located off the stabilized platform.
Problems arise in determining the line-of-sight provided by the laser beam due to inherent jitter present in the beam. The jitter may be derived from such causes as vibration, heating effects or feedback problems within the laser source.
Some prior art methods of producing a stabilized output beam have employed two optical channels comprising a plurality of penta-prisms, beamsplitters, and roof prisms totaling eight cemented components. Such a configuration is both complex to manufacture and costly due to the number of optical components. Furthermore, in order to achieve high angular system accuracy, for example, in the nanoradian range, the precision required in manufacturing and assembling these components is well beyond the capability of the present state-of-the-art.
It would, therefore, be an improvement in the art to provide a device which may be utilized accurately to determine a reference axis, or line-of-sight, of an optical beam in the presence of optical source jitter.
It would also be an improvement in the art to provide a highly accurate and inexpensive device which may be employed to generate optical reference information in the presence of optical source jitter.